Blood Pressure Dipping Status Research Articles

Identifying an acceptable number of ambulatory blood pressure measurements for accuracy of average blood pressure and nocturnal dipping status.

We aimed to identify the minimum number of ambulatory blood pressure (ABP) measures to accurately determine daytime and nighttime systolic blood pressure (BP) averages and nocturnal dipping status (i.e., relative daytime:nighttime change). A total of 43 midlife participants wore an ABP monitor for 24 h with measurements every 20/30 min during the daytime/nighttime, as identified by a sleep diary. We calculated daytime/nighttime systolic BP average and dipping status from all available measurements per participant (i.e., normative data). We then calculated daytime and nighttime BP per participant based on a random selection of 8-20 and 4-10 measurements and replicated random selections 1,000 times. We calculated accuracy by checking the proportion from 1,000 different randomly selected samples for a particular number of measurements that systolic BP was ±5 mmHg of normative data, and dipping status remained unchanged for each participant compared with the normative value. The best fit for the regression model estimated the minimal number of measurements for an accuracy of 95% in BP averages. For a 95% accuracy in estimating daytime and nighttime systolic BP, 11 daytime and 8 nighttime measurements were required. The highest accuracy for dipping status was 91.6 ± 13.4% using 20 daytime and 10 nighttime measures, while the lowest was (83.4 ± 15.1%) using 8 daytime and 4 nighttime measures. In midlife adults, 11 daytime and 8 nighttime measurements are likely enough to calculate average systolic BPs accurately. However, no minimum number is suggested to accurately calculate dipping status.NEW & NOTEWORTHY We found that a minimum of 11 blood pressure (BP) measures are necessary to calculate an accurate average daytime BP, and 8 nighttime measures are necessary to calculate an accurate nighttime average if 95% accuracy is acceptable. Regarding BP dipping status, the current recommendations (20 daytime/7 nighttime) inaccurately classified the dipping status 10.5% of the time, suggesting that guidelines may need to be updated to classify patients as nocturnal dippers or nondippers correctly.

Sex difference in nocturnal blood pressure dipping in adolescents with varying degrees of adiposity

BackgroundFor adolescents, abnormal dipping patterns in blood pressure (BP) are associated with early-onset organ damage and a higher risk of cardiovascular disorders in adulthood. Obesity is one of the most common reasons for abnormal BP dipping in young people. However, it is unknown whether the severity of obesity is associated with BP dipping status and whether this association is sex-dependent.Methods499 participants between 12 and 17 years old with overweight or obesity underwent ambulatory blood pressure monitoring (ABPM) between April 2018 and January 2019 in Beijing and Baoding. Participants were grouped by body mass index (BMI) into overweight (BMI 85th–95th percentile), obese (BMI ≥ 95th percentile) and severely obese (BMI ≥ 120% of 95th percentile or ≥ 35 kg/m2) groups. Non-dipping was defined as a < 10% reduction in BP from day to night. The interaction effect between sex and obesity degree was also analyzed.Results326 boys and 173 girls were included, of whom 130 were overweight, 189 were obese, and 180 were severely obese. Girls with severe obesity had a higher prevalence of non-dipping, but boys showed no significant differences in BP dipping status between obesity categories. In addition, as obesity severity went up, a more evident increase in night-time SBP was observed in girls than in boys.ConclusionsSeverely obese is associated with a higher prevalence of non-BP dipping patterns in girls than in boys, which suggests that the relationship between the severity of obesity and BP dipping status might be sex-specific.

Impaired nocturnal blood pressure dipping in patients with type 2 diabetes mellitus with microvascular complications

Hypertension is a common comorbidity of type 2 diabetes mellitus (T2DM). Both conditions are associated with an increased cardiovascular risk, which is reduced by tight blood pressure (BP) and glycemic control. However, non-dipping BP status continues to be an enduring cardiovascular risk factor in T2DM. This study aimed to investigate the association between microvascular complications of diabetes and nocturnal dipping of BP. We compared 13 type 2 diabetic patients with (DM+) and 67 diabetic patients without (DM−) manifest microvascular disease. BP dipping status was assessed from 24-hour ambulatory BP measurements. DM+ patients were older 60.3 ± 8.7 years vs. 58.3 ± 10.4 years ( P = 0.47). There was no significant difference between the two groups in diabetes control, clinical systolic BP and clinical diastolic BP. Dyslipidemia was significantly more present in DM+, 84.7% vs. 47.8% ( P = 0.015). DM+ patients had significantly higher daytime and 24-hour mean SBP than DM− patients with P = 0.02 and 0.023 respectively. Pulse pressure was significantly ( P = 0.03) higher in DM+. The nocturnal blood pressure profile in DM+ was “non-dipper” and “reverse dipper” respectively in 69% and 15% of patients versus 27% and 11% in DM− ( P = 0.003; P = 0.026). Our findings once again highlighted the importance of ambulatory BP monitoring and targeted antihypertensive therapy directed toward to restore normal circadian BP in patients with T2DM.

The faecal abundance of short chain fatty acids is increased in men with a non-dipping blood pressure profile

Background and aims Gut microbiota (GM) has been involved in the pathophysiology of hypertension (HT), notably via short chain fatty acids (SCFAs). Among the clinical manifestations of HT, the absence of a significant drop in night-time blood pressure (BP) (also known as the non-dipping BP profile) has been associated with poor renal and cardiovascular outcomes. The putative link between GM-derived metabolites and BP dipping status is still unknown. Methods Male volunteers (n = 44) were prospectively subjected to 24-hour ambulatory blood pressure monitoring, stool sample collection and a medical questionnaire. Metabolomics analyses of stool samples were conducted using Nuclear Magnetic Resonance (NMR). Results Higher amounts of acetate, butyrate and propionate were found in the stools of non-dippers (n = 12) versus dippers (n = 26) (p = 0.0252, p = 0.0468, and p = 0.0496, respectively; n = 38 in toto). NMR spectral data were not interpretable in 5 dippers and 1 non-dipper. A similar significant association was found when including only patients without anti-HT medications (p = 0.0414, p = 0.0108, and p = 0.0602, respectively; n = 21 in toto). A not significant trend was observed when focussing only on HT patients without anti-HT medications (p = 0.0556; n = 14 in toto). Conclusion Our pilot study highlights a putative link between GM-derived SCFAs and the BP dipping status, independently of the BP status itself or the anti-hypertensive medications.

Defining the nocturnal period in 24-h ambulatory blood pressure monitoring: a comparison of three methods.

The purpose of our study was to compare three definitions of ambulatory blood pressure (BP) nocturnal period and to assess their agreement in determining nocturnal BP dipping patterns. We investigated 69 subjects with metabolic syndrome, aged 50-55 years. In all subjects, we assessed 24-h BP monitoring, electrocardiogram and actigraphy profiles. The nocturnal period was defined in three ways: as a fixed narrow nighttime period from 01:00 to 06:00, as a self-reported sleeping period and as a disappearance and onset of physical activity recorded by the actigraph. Our study revealed a significant discrepancy between the self-reported and actigraphy-based nocturnal periods (P < 0.001). In addition, different definitions of the nighttime yielded significant differences in determining nondipping, extreme dipping and dipping BP patterns, the identification of the latter being affected the most. The actigraphy-based approach best aligned with the fixed-time determination of the nocturnal period: Cohen's kappa coefficient for the nondipping pattern was 0.78 (0.58-1), for the dipping pattern 0.75 (0.59-0.91) and for the extreme dipping pattern 0.81 (0.65-0.97). In comparison to the self-reported determination of the nocturnal period, using the actigraphy-based approach resulted in reclassifying the nocturnal BP pattern in 20.3% of subjects. The lack of agreement between fixed-time, self-reported and actigraphy-based determinations of the nighttime period affects the identification of the nocturnal BP patterns. In comparison to the self-reported nocturnal period estimation, the actigraphy-based approach results in the reclassification of BP dipping status in every fifth subject.

Relationship between nocturnal blood pressure patterns and end organ damage and diastolic dysfunction in heart transplant recipients.

We assessed the relationship between circadian blood pressure (BP) patterns and clinical outcomes in a contemporary cohort of adult heart transplant recipients. This retrospective, cross-sectional study included adult heart transplant recipients at least 6months post-transplant. Ambulatory BP measurements were recorded over 24hours. Nondippers were defined as a decline in average nighttime BP≤10% compared with daytime. Primary outcomes were the presence of end organ damage, that is, microalbuminuria, chronic kidney disease, and/or left ventricular hypertrophy. Secondary outcomes were measures of diastolic dysfunction (ie, mitral valve deceleration time, e/e', E/A, and isovolumetric relaxation time), microalbumin/creatinine ratio, eGFR, interventricular septal thickness, and left ventricular posterior wall thickness. Of 30 patients, 53.3% (n=16) were systolic nondippers and 40% (n=12) were diastolic nondippers. Diastolic nondippers had three times higher urine microalbumin/creatinine ratios than diastolic dippers (P=.03). Systolic nondippers had 16.3% lower mitral valve deceleration time (P=.05) than systolic dippers, while diastolic nondippers had 20.4% higher e/e' (P=.05) than diastolic dippers. There were no significant relationships between BP dipping status and any of the primary outcomes. These data suggest that systolic and diastolic nondipping BP patterns are associated with subclinical kidney damage and diastolic dysfunction in heart transplant recipients.

Ambulatory Blood Pressure Monitoring: Profiles in Chronic Kidney Disease Patients and Utility in Management.

Optimal control of blood pressure (BP) may reduce the risk of progression of CKD. Misclassification of hypertension (HTN) and status of control may result in suboptimal management. Clinic or home BP may overestimate or underestimate status of control compared with ambulatory BP monitoring (ABPM), which is considered the gold standard. The latter relates not only to the superiority of ABPM concerning outcome prognosis but also to its ability to accurately diagnose white coat and masked HTN, which is critical in assuring adequate BP control. However, ABPM has not gained widespread use in practice because of limited third-party reimbursement and a paucity of high quality randomized controlled intervention studies evaluating its use. Herein, we review HTN phenotypes that have been identified in patients with CKD, and the potential value of ABPM in this high-risk population.

Impaired nocturnal blood pressure dipping in patients with type 2 diabetes mellitus.

Hypertension is a common comorbidity of type 2 diabetes mellitus (T2DM). Both conditions are associated with an increased cardiovascular risk, which is reduced by tight blood pressure (BP) and glycemic control. However, nondipping BP status continues to be an enduring cardiovascular risk factor in T2DM. Cardiovascular autonomic neuropathy and endothelial dysfunction have been proposed as potential mechanisms. This study tested the hypothesis that microvascular disease rather than cardiovascular autonomic neuropathy interferes with the physiological nocturnal BP reduction. Cardiovascular autonomic function and baroreflex sensitivity were determined in 22 type 2 diabetic patients with (DM+) and 23 diabetic patients without (DM-) manifest microvascular disease. BP dipping status was assessed from 24-hour ambulatory BP measurements. Sixteen nondiabetic subjects served as controls (CTRL). Cardiovascular autonomic function was normal in all subjects. Baroreflex sensitivity was lower in DM- compared with CTRL (7.7 ± 3.3 vs. 12.3 ± 8.3 ms·mm Hg-1; P < 0.05) and was further reduced in DM + (4.6 ± 2.0 ms·mm Hg-1; P < 0.01 vs. DM- and CTRL). The nocturnal decline in systolic and diastolic BP was blunted in DM- (12% and 14% vs. 17% and 19% in CTRL; P < 0.05) and even more so in DM+ (8% and 11%; P < 0.05 vs. DM- and P < 0.001 vs. CTRL). A nocturnal reduction in pulse pressure was observed in CTRL and DM- but not in DM+ (P < 0.05 vs. DM- and P < 0.01 vs. CTRL). In T2DM, progression of microvascular disease interferes with the normal nocturnal BP decline and coincides with a persistently increased pulse pressure and reduced baroreflex sensitivity, contributing to their increased cardiovascular risk.

Nondipping pattern on 24-h ambulatory blood pressure monitoring is associated with left ventricular hypertrophy in chronic kidney disease.

Few studies have assessed the role of 24-h ambulatory blood pressure monitoring (ABPM) in adults with nondialysis chronic kidney disease (CKD). We examined the potential determinants of left ventricular hypertrophy (LVH) and mass index (LVMI) in this population. We carried out a cross-sectional study on 69 stage 3b-5 CKD adults who had ABPM and transthoracic echocardiography performed simultaneously. Hypertension (HT) was defined as 24 h blood pressure (BP) of at least 130/80 mmHg. ABPM parameters considered were BP dipping status, BP load, and the BP night-time/daytime ratio. We performed stepwise backward multivariate linear and logistic regression to assess the determinants of LVH and LVMI. ABPM parameters were considered the main independent variables, whereas HT, angiotensin-converting enzyme inhibitor/angiotensin II receptor antagonist use, glomerular filtration rate of less than 30 ml/min/1.72 m, diabetes, smoking, age, sex, hemoglobin, and parathyroid hormone levels were considered covariates. LVH was present in 22 (31.8%) patients. In linear regression analysis, systolic [β=-13.8, 95% confidence interval (CI)=-26.3 to -1.3, P=0.031] and mean (β=-13.5, 95% CI=-25.7 to -1.2, P=0.031) nondipping status was associated with increased LVMI. BP load and night-time/daytime ABPM ratio were not associated with LVMI. In logistic regression analysis, systolic nondipping status (odds ratio=0.27, 95% CI=0.08-0.91, P=0.036) was associated with LVH. Among covariates, estimated glomerular filtration rate of less than 30 ml/min/1.72 m and HT were associated with LVH and increased LVMI. At 1-year follow-up, mean nondipping status on the initial ABPM remained associated significantly with increased LVMI (β=-19.8, 95% CI=-36.6 to -3.0, P=0.022). These data confirm the high incidence of LVH among nonrenal replacement therapy CKD patients and suggest that the nondipping phenomenon on ABPM is associated independently with LVH and increased LVMI in this population.

NON-DIPPING PHENOMENON MEASURED BY 24H-AMBULATORY BLOOD PRESSURE MONITORING IS A STRONG PREDICTOR OF LEFT VENTRICULAR HYPERTROPHY IN CHRONIC KIDNEY DISEASE

Objective: Few studies have assessed the role of 24 h ambulatory blood pressure monitoring (ABPM) in adults suffering from non-dialysis chronic kidney disease (CKD). We examined potential determinants of left ventricular hypertrophy (LVH) and mass index (LVMI) in this population. Design and method: We conducted a cross-sectional study on 69 stage 3b-5 CKD adults who had ABPM and transthoracic echocardiography performed simultaneously. Hypertension (HT) was defined as 24 h blood pressure (BP) > or = 130/80 mmHg. ABPM parameters considered were BP dipping status, BP load and BP nighttime/daytime ratio. We conducted stepwise backward multivariate linear and logistic regression to assess determinants of LVH and LVMI. ABPM parameters were considered main predictors whereas HT, ACEI/ARAII use, GFR < 30 ml/min/1.72m2, diabetes, smoking, age, gender, Hb and PTH levels were considered covariates. Results: LVH was present in 22 (31.8%) patients. In linear regression analysis, systolic (β=−13.8, 95% CI = −26.3; −1.3, p = 0.031) and mean (β=−13.5, 95% CI = −25.7; −1.2, p = 0.031) dipping statuses were negatively associated with LVMI. BP load and nighttime/daytime ABPM ratio were not associated with LVMI. In logistic regression analysis, systolic dipping status (OR = 0.27, 95% CI = 0.08; 0.91, p = 0.036) was negatively associated with LVH. Amongst covariates, eGFR < 30 ml/min/1.72m2 and HT were positively associated with LVH and LVMI. At one-year follow-up, mean dipping status on the initial ABPM remained significantly associated with LVMI (β=−19.8, 95% CI = −36.6; −3.0, p = 0.022). Conclusions: These data confirm the high incidence of LVH amongst non-RRT CKD patients and suggest that non-dipping phenomenon on ABPM is an independent and strong predictor of LVH and LVMI in this population.

The Impact of Blood Pressure Dipping Status on Cognition, Mobility, and Cardiovascular Health in Older Adults Following an Exercise Program.

Objectives: To determine whether a dual-task gait and aerobic exercise intervention differentially impacted older adults with normal blood pressure (BP) dipping status (dippers) compared to those with nondipping status (nondippers). Methods: This study was a secondary analysis involving participants (mean age = 70.3 years, 61% women) who attended a laboratory-based exercise intervention over a 6-month period (40 min/day and 3 days/week). Participants were assessed in measures of cognition, mobility, and cardiovascular health at baseline, 3, 6, and 12 months (after a 6-month no-contact follow-up). Results: We observed improvements in cognition in both groups at 6 and 12 months, although no between-group differences were seen. Nondippers demonstrated superior improvements in usual gait velocity and step length after the exercise intervention compared to dippers. Dippers reduced daytime systolic BP at 6 and 12 months to a greater extent than nondippers. Discussion: BP dipping status at baseline did not influence exercise benefits to cognition but did mediate changes in mobility and cardiovascular health.

DOES A 6-MONTH DUAL-TASK GAIT AND AEROBIC EXERCISE INTERVENTION DIFFERENTIALLY IMPACT OLDER ADULTS WITH NORMAL VERSUS NON-NORMAL BLOOD PRESSURE DIPPING STATUS?

We investigated the effects of a 6-month combined dual-task (DT) gait and aerobic exercise (AE) intervention among older adults without dementia presenting normal blood pressure (BP) dipping status (i.e., >10% drop in systolic BP from daytime to nighttime) and those with non-dipping status (i.e., <10% drop in systolic BP from daytime to nighttime) on measures of cognition, mobility, and cardiovascular health. A secondary analysis was performed in a sample of 79 [70.3 (6.6) yr, Montreal Cognitive Assessment: 25 (2.4), 61% females,] participants who attended to a laboratory-based exercise intervention 40 min/day, 3 days/weeks for 6 months. Assessments occurred at baseline, 3 months, 6 months and 12 months (i.e., after a 6-month no-contact follow-up). Cognition measures [standardized global cognitive function (GCF), executive function (EF), processing speed, memory, verbal fluency], mobility (usual and DT gait characteristics) and cardiovascular health (carotid intima-media thickness and arterial compliance) were analyzed using linear mixed effects models controlling for age, education, gender, presence of hypertension and diabetes. At baseline, 35 participants met the criteria for normal dipping status (dippers), whereas 44 met the criteria for non-dipping status (nondippers). Both groups improved in GCF, memory and verbal fluency at all time points; at 6 and 12 months, both groups improved in EF and processing speed. No differences between groups in cognition were observed at any follow-up time points. For mobility measures, nondippers showed improvements in usual gait velocity and step length at all time points, which led to differences between groups at 6 months, favouring nondippers. In contrast, dippers reduced DT gait variability to a greater extent at all time points, with differences between groups occurring at 12-months. Additionally, dippers and nondippers increased DT gait velocity at 6-months, however, only nondippers increased DT step length over the same period, with no differences between groups. Regardless of BP dipping status, a 6-month combined DT gait and AE intervention in older adults without dementia improved cognition with no change in cardiovascular health, while those presenting non-dipping status yielded superior improvements in mobility.

MPS 05-04 IMPAIRED NOCTURNAL BLOOD PRESSURE DECLINE IN TYPE 2 DIABETES MELLITUS

Objective: Hypertension is a common comorbidity of type 2 diabetes mellitus (T2DM) and both are associated with increased cardiovascular risk, which is reduced by tight blood pressure (BP) and glycemic control. However the non-dipping BP status, defined as a nocturnal BP decline of less than 10% compared with daytime BP, is common in T2DM and remains an enduring cardiovascular risk factor. Cardiovascular autonomic neuropathy and endothelial dysfunction have been proposed as potential mechanisms. We hypothesized that the degree of microvascular disease rather than cardiovascular autonomic neuropathy interferes with the normal nocturnal reduction in BP. Design and Method: Cardiovascular autonomic function and time-domain baroreflex sensitivity (xBRS) were determined in 22 diabetic patients with (DM+) and 23 diabetic patients without (DM−) manifest microvascular disease. BP dipping status was determined from 24-hour ambulatory BP measurements. Sixteen non-diabetic subjects served as controls (CTRL). Results: None of the subjects demonstrated parasympathetic or sympathetic cardiovascular dysfunction. xBRS was lower in DM− patients compared to CTRL (7.7 ± 3.3 vs. 12.3 ± 8.3 ms·mmHg−1; P < 0.05), and further reduced in DM+ patients (4.6 ± 2.0 ms·mmHg−1; P < 0.01 vs. DM− and CTRL). The nocturnal decline in systolic and diastolic BP in DM− was blunted (12% and 14% vs. 17% and 19% in CTRL; P < 0.05) and even more so in DM+ (8% and 11%; P < 0.05 vs. DM− and P < 0.001 vs. CTRL). The percentages of non-dippers were 37%, 70% and 86% respectively in the CTRL, DM− and DM+ group. A nocturnal reduction in pulse pressure was observed in CTRL and DM− but not in DM+ patients (P < 0.05 vs. DM− and P < 0.01 vs. CTRL). Conclusions: In T2DM patients, the degree of microvascular disease rather than CAN interferes with the normal nocturnal reduction in BP with a persistently increased pulse pressure, and coincides with reduced baroreflex sensitivity, contributing to their increased cardiovascular risk.

Blood Pressure and Cardiovascular Health in College Students and Campus Faculty/Staff

Previous research indicates that cardiovascular (CV) disease mortality has decreased in populations ages 55‐74, but has not for younger groups, suggesting a need for research in CV health in younger adults. We compared CV health measures between relatively healthy young (college students) and middle‐aged (faculty/staff) adults who were matched for body mass index (BMI) and blood pressure (BP) dipping status. Measures of CV health, including: VO2max, clinical BP, ambulatory blood pressure (ABP), BMI, and fasted plasma glucose/cholesterol were measured in students (n=10, 20.2±0.6 yrs) and faculty/staff (n=9, 44.8±8.3 yrs) of a small college campus. There was no difference in VO2max, glucose,/cholesterol, or clinical BP measures between the groups, but there were differences in diastolic 24 hr ABP, diastolic daytime ABP, and diastolic nighttime ABP (p&lt;0.05 for all). In students, we found no relationships between ABP and CV health variables. However, in faculty/staff, there was a relationship between 24 hr systolic ABP and daytime systolic ABP with glucose, HDL, and triglycerides (p&lt;0.05 for all). Our results indicate that, although there are no differences in BP dipping status, BMI, and clinical BP measures between the groups, there is a relationship between glucose, HDL, and triglycerides with ABP in only the faculty/staff adult group. This suggests that other measures, not examined in this study, may differ between the two groups.

Abstract P020: Associations of Markers of Inflammation with Nocturnal BP Dipping Status Using Two Common Dipping Definitions: the Genetic Epidemiology Network of Arteriopathy

Background: Compared to those with natural nocturnal blood pressure (BP) decreases, those lacking nocturnal BP decreases (“non-dippers”) are at greater risk of cardiovascular disease (CVD). Substantial evidence also supports a role of chronic systemic inflammation in the pathogenesis of CVD. The purpose of this study was to examine associations of markers of inflammation with two common definitions of BP dipping status using 24-hour ambulatory blood pressure (AMBP) readings. Methods: AMBP monitoring and assays of C-reactive protein (CRP), interleukin-6 (IL-6), e-selectin, tissue inhibitor of metalloproteinase-2 (TIMP-2), and a selection of thirteen other inflammatory-pathway biomarkers were performed in 722 participants (mean age 64 [range 42-83] years, 36% men, 39% black, 83% hypertensive) in the Genetic Epidemiology Network of Arteriopathy (GENOA) Study (2001-2004). Non-dippers were classified using two common definitions: (1) nocturnal systolic and diastolic BP both decreased by &lt;10% compared to daytime values [“dual non-dippers”, n=161 (22%)], and (2) nocturnal SBP decreased by &lt;10% [“systolic non-dippers”, n=380 (53%)]. Logistic regressions, fit with generalized estimating equations to account for sibship clustering, yielded odds ratios (OR) of dipping status for log-transformed inflammatory biomarkers, adjusted for age, race, and sex. Results: IL-6 (range 0-37 pg/ml) was associated with dual non-dipping status (OR=1.55 [95%CI: 1.03, 2.32] p=0.035), translating into a 55% increase in the likelihood of being a dual non-dipper for every approximate doubling of IL-6. IL-6 (OR=1.63 [1.13, 2.35] p=0.009) and CRP (OR=1.35 [1.08,1.68] p=0.008) overall, as well as e-selectin (OR=0.49 [0.28, 0.87] p=0.014) and TIMP-2 (OR=0.54 [0.30,0.98] p=0.041) in hypertensive subjects were associated with systolic non-dipping status. Conclusions: These results suggest that non-dipping classification should be approached with prudence, as the two different criteria may influence conclusions about predictive marker associations. In addition, markers involved in direct versus inhibitory inflammation pathways may operate differentially across patient subgroups. Our findings support the link between inflammation and non-dipping circadian BP patterns and provide novel information on markers and definitions which may be useful for early detection and subsequent prevention of CVD.

Non dipping blood pressure pattern is related to an increase in daytime distal skin temperature

Introduction The circadian pattern of blood pressure (BP) is closely associated to sleep-wake cycle, target organs damage and cardiovascular events. Thus, BP circadian pattern diagnosis should be based on an objective procedure to determine patient’s actual sleep and wake time instead of standard sleep schedules. Wrist temperature (WT) rhythm is subordinated to the master circadian clock and it is related to autonomic balance, thermoregulation, sleep propensity and sleep wake cycle and also responds to postural changes. Thus, the purpose of this research is to determine accurately the BP pattern using circadian ambulatory monitoring and the association between WT rhythm and the BP dipping status. Materials and methods WT, Activity (A) and Position (P) were recorded during five days in 33 healthy subjects, aging from 21 to 63 years old, by means of two data loggers, an Ibuttom device (ThermoChron®,) and a Hobo actimeter (Hobo® Pendant G, Acceleration Data Logger). Ambulatory BP was determined during 24 h using a BP monitor (Spacelabs® Medical) with a sampling rate of one measure every 20 min during day and every 40 min during night. An alertness variable (TAP) was calculated averaging normalized values for WT, A and P. Sleep time was automatically considered when P 30 o and A 25 o /min. Results Non-dipper subjects showed higher systolic BP during nighttime (124.62 ± 6.00 mmHg vs 112.36 ± 2.50 mmHg) as it was expected. In addition, we found a significant increase in WT during daytime (33.81 ± 0.18 o C vs 32.88 ± 0.19 o C), but not during nighttime, and higher TAP values during nighttime (0.19 ± 0.03 a.u. vs. 0.14 ± 0.01 a.u.) in non-dipper compared with dipper subjects, while no differences were found for activity and body position. Conclusion Considering individual sleep pattern when evaluating BP pattern provides a more accurate diagnosis of dipping pattern. The use of P, A and WT information might change the interpretation of ambulatory BP monitoring data and improve the diagnosis of circadian BP pattern. Furthermore, circadian monitoring could distinguish between dipper and non-dipper pattern using daytime WT values. Acknowledgements Study supported by RETICEF (RD12/0043/0011), MINECO (BFU2010–21945-C02–01), and INNPACTO (IPT-2011–0833-900000) with FEDER cofounding to JAM, and a research fellowship to Antonio Martinez-Nicolas (University of Murcia).

Can ambulatory blood pressure serve as a biomarker for presence of chronic kidney disease?

Can ambulatory blood pressure serve as a biomarker for presence of chronic kidney disease?

Ambulatory Blood Pressure and Physical Activity in Heart Failure

This observational study used repeated measures over 24 hr to investigate ambulatory blood pressure (BP) and physical activity (PA) profiles in community-based individuals with heart failure (HF). The aims were to (a) compare BP dipping and PA between two groups of HF patients with different functional statuses, and (b) determine whether the strength of the association between ambulatory BP and PA varies by functional status in HF. Ambulatory BP was measured every 30 min with a SpaceLabs 90207; a Basic Motionlogger actigraph was used to measure PA minute-by-minute. Fifty-six participants (54% female, age 66.96 + or - 12.35 years) completed data collection. Functional status was based on New York Heart Association (NYHA) ratings. Twenty-seven patients had no limitation of PA (NYHA Class I HF), whereas 29 had some limitation of PA but no discomfort at rest (NYHA Class II or III HF). Patients with Class I HF had a significantly greater degree of BP dipping than those with Class II/III HF after controlling for left ventricular ejection fraction. In a mixed-model analysis, PA was significantly related to ambulatory systolic and diastolic BP and mean arterial pressure. The strength of the association between PA and BP was not significantly different for the two groups of patients. These findings demonstrate differences between Class I and Class II/II HF in BP dipping status and ambulatory BP but not PA. Longitudinal research is recommended to improve understanding of the influence of disease progression on changes in 24-hr PA and BP profiles of patients with HF.

Association of Diurnal Blood Pressure Pattern With Risk of Hospitalization or Death in Men With Heart Failure

Background An altered diurnal blood pressure (BP) pattern has been linked to the risk of developing heart failure (HF). We tested whether an altered diurnal BP pattern is associated with adverse outcomes (death or hospitalization for HF exacerbation) in patients with HF. Methods and Results A total of 118 patients with HF were enrolled from a tertiary care HF clinic and followed for death or HF hospitalization for up to 4 years; 24-hour ambulatory BP was monitored. Forty patients (34%) had a normal BP dipping pattern (night–day ambulatory BP ratio < 0.9), 44 patients (37%) had a nondipping pattern (0.9 ≤ night–day ambulatory BP ratio < 1.0), and 34 patients (29%) had a reverse dipping BP pattern (night–day ambulatory BP ratio ≥ 1.0). A total of 39 patients had an adverse outcome. Adverse outcome rates were the lowest in dippers and the highest in reverse dippers (log rank P = .052). Predictors of adverse outcomes, selected on the basis of log likelihood contrast, were as follows: New York Heart Association functional class (hazard ratio [HR] 1.96, 95% confidence interval [CI] 1.11–3.44), anemia (HR 2.50, 95% CI 1.23–5.08), and dipping status (HR 1.65, 95% CI 1.08–2.50). Conclusion In addition to other traditional predictors, BP dipping status may be an important prognostic factor in HF.